No it isn't:

$ perl -MO=Deparse,-p -e ' ($t[0] == $s[0] && $t[0] == $e[0]) ? $r[0] 
+= 1 : $r[0] = 0; '
(((($t[0] == $s[0]) && ($t[0] == $e[0])) ? ($r[0] = 1) : $r[0]) = 0);

-e syntax OK
$ perl -MO=Deparse,-p -e ' $r[0] = ($t[0] == $s[0] && $t[0] == $e[0]) 
+? 1 : 0; '
($r[0] = ((($t[0] == $s[0]) && ($t[0] == $e[0])) ? 1 : 0));
-e syntax OK
[download]

Update: for example:

$ perl -le'
@test = ( [ 10, 12, 14 ], [ 12, 12, 14 ], [ 12, 14, 14 ], [ 12, 12, 12
+ ], [ 14, 10, 14 ] );
for ( @test ) {
    ( $t, $s, $e ) = @$_;
    print "1:  $t  $s  $e";
    $r = undef;
    ($t == $s && $t == $e) ? $r = 1 : $r = 0;
    print "2:  $t  $s  $e  $r";
    $r = undef;
    $r = ($t == $s && $t == $e) ? 1 : 0;
    print "3:  $t  $s  $e  $r\n";
    }
'
1:  10  12  14
2:  10  12  14  0
3:  10  12  14  0

1:  12  12  14
2:  12  12  14  0
3:  12  12  14  0

1:  12  14  14
2:  12  14  14  0
3:  12  14  14  0

1:  12  12  12
2:  12  12  12  0
3:  12  12  12  1

1:  14  10  14
2:  14  10  14  0
3:  14  10  14  0
[download]